Compressor machines in general, and particularly scroll compressors, are often disposed in a hermetic or semi-hermetic shell which defines a chamber within which is disposed a working fluid. A partition within the shell often divides the chamber into a discharge-pressure zone and a suction-pressure zone. In a low-side arrangement, a scroll assembly is located within the suction-pressure zone for compressing the working fluid. Generally, these scroll assemblies incorporate a pair of intermeshed spiral wraps, one or both of which are caused to orbit relative to the other so as to define one or more moving chambers which progressively decrease in size as they travel from an outer suction port towards a center discharge port. An electric motor is normally provided which operates to cause this relative orbital movement.
The partition within the shell allows compressed fluid exiting the center discharge port of the scroll assembly to enter the discharge-pressure zone within the shell while simultaneously maintaining the integrity between the discharge-pressure zone and the suction-pressure zone. This function of the partition is normally accomplished by a seal which interacts with the partition and with the scroll member defining the center discharge port.
The discharge-pressure zone of the shell is normally provided with a discharge-fluid port which communicates with a refrigeration circuit or some other type of fluid circuit. In a closed system, the opposite end of the fluid circuit is connected with the suction-pressure zone of the shell using a suction-fluid port extending through the shell into the suction-pressure zone. Thus, the scroll machine receives the working fluid from the suction-pressure zone of the shell, compresses the working fluid in the one or more moving chambers defined by the scroll assembly, and then discharges the compressed working fluid into the discharge-pressure zone of the compressor. The compressed working fluid is directed through the discharge port through the fluid circuit and returns to the suction-pressure zone of the shell through the suction port.
A lubricant (e.g., oil) sump can be employed in the shell of the compressor to store the lubricant charge. The sump can be placed in either the low-pressure zone or the high-pressure zone. The lubricant serves to lubricate the moving components of the compressor and can flow with the working fluid through the scroll assemblies and be discharged along with the working fluid into the discharge-pressure zone of the compressor. The temperature of the lubricant being discharged, along with that of the working fluid, is elevated. Cooling the lubricant prior to flowing back through the compressor and lubricating the components therein can reduce suction-gas superheat, thereby improving compressor volumetric efficiency and providing better performance. The reduced lubricant temperature may also improve compressor reliability by cooling the suction gas and the motor. Cooling the lubricant can also keep the viscosity of the lubricant at a desirable level for maintaining oil film thickness between moving parts.
Within the compressor, the lubricant is provided to the various moving components. Improving the distribution of the lubricant throughout the compressor can advantageously improve the performance and/or longevity of the compressor.
Within the compressor, the proper alignment of the various components relative to one another can improve the performance of the compressor and/or reduce the sound generated by the compressor. Improving the alignment between the various components, such as the non-orbiting scroll member, the bearings, and the motor, can improve the performance and/or reduce the sound generated by the compressor. The compressors typically use numerous discrete components that are assembled together within the shell to provide the alignment. The use of these numerous separate and discrete components, however, increases the potential for inaccuracy in the alignment of the components and, further, can be more expensive or time consuming to manufacture as tighter tolerances for the various components are required to produce the desired alignment.